It could be the last uninterrupted stretch of pro football that any of us sees for a long, long time.

The league’s 2010 slate officially kicked off this weekend when the Browns and Cowboys opened training camp, and the black cloud of a lockout next year hasn’t gone away.

With the NFL riding an unprecedented crest of popularity that has turned the sport into a $9 billion-a-year behemoth, one would think the owners and players could find a common-sense solution that wouldn’t threaten that golden goose and endanger an entire season.

Guess again.

“It’s kind of difficult to process it, really,” Jets center Nick Mangold told The Post during offseason workouts. “You start to worry that this time next year, there’s not going to be any [NFL] football. You look at the money and wonder how it got to this point, but here we are.”

The two sides appear to have found some common ground on a variety of important issues ranging from a rookie salary cap to enhanced drug testing to retiree pensions to improved player safety, so that is reason for encouragement.

But overall player salaries remain the single biggest roadblock to a new collective bargaining agreement between the owners and the NFL Players Association, and both sides seem to be digging in for the long, ugly slog.

“I don’t know that I’ve ever seen the owners as committed as they are now,” Giants co-owner John Mara told The Post at the recent NFL spring meeting. “We are truly a unified group, and I hope the union realizes that.”

That unity already has produced something few league observers ever thought would happen in the NFL’s post-1994 era — a season without a salary cap.

But that’s exactly what happened when the owners opted out of the current CBA, and the players have seen payrolls around the league plummet as owners conserve cash for what could be the NFL’s nuclear winter of 2011.

The sticking point remains the owners’ insistence that the players’ overall compensation percentage be rolled back, with those cost savings then applied to the enormous sums that many owners have plowed into stadium construction (see: $1.7 billion New Meadowlands Stadium, courtesy of the Giants and Jets).

The owners say increased revenue from all the new stadiums will expand the money pile for everyone involved, including the players, but the union views it as an unacceptable 18 percent pay cut across the board.

The NFLPA is digging in behind new union chief DeMaurice Smith, an attorney who is much less league friendly than late predecessor Gene Upshaw, and is doing so while lobbing legal challenges and charges of dirty tricks and collusion against the owners.

“Over the last two years, the NFL has done nothing but prepare for this lockout,” Smith told The Post recently. “This isn’t a work stoppage — this is a lockout.”

Most industry observers doubt the players’ ability to stick together once a lockout starts and the paychecks stop in the fall of 2011. History isn’t on the NFLPA’s side, considering how quickly their brethren caved in the 1987 strike and how their NBA counterparts did much the same during pro basketball’s 1998 lockout.

Can’t we all just get along? Considering the NFL overall has never been richer or more popular, it’s a fair question.